1. Field of the Invention
This invention relates to table mounted, power circular saws which are primarily intended to perform a chopping function.
2. Description of the Prior Art
Traditionally chop saws are pivotably mounted on a saw table, between a raised rest position and a lowered operational position. For safety reasons, it is desirable to provide a hood to cover the saw blade when the saw is in the rest position. Convenience dictates that any such blade guard should be mounted in a maner such that it will be swung clear of the saw blade when the saw is pivoted from its rest position to its operational position. Prior art devices, such as German Offenlegungsschrift No. 28 29 297, have attempted to solve this problem by coupling the swinging hood to a saw table with a cable in order to pivot the hood to clear the blade when the saw unit is lowered to its operational position.
An inherent problem with such prior art devices is that when the saw unit is in the raised rest position, the blade guard hampers attempts to change the saw blade. Likewise, it is difficult to change a saw blade in the operational position because the saw table gets in the way.
When the chop saw is not in use, it is also desirable for safety reasons to lock the saw-unit in its rest position with the blade covered. Prior art locking systems, such as the one disclosed in German Gebrauchsmuster 74 20 476, keep the raised saw unit in the rest position by means of a locking element that engages a stationary locking surface. To be released, the locking element must displace a spring. In such an arrangement, the entire weight of the saw unit rests upon the locking element, which accordingly must be very rugged in order to prevent damage when the user inadvertently attempts to force the saw-unit down while the locking element remains engaged to the locking surface.
The instant invention has overcome many of the disadvantages of prior art devices by providing a linkage system which effectively clears the blade guard from the saw blade when the chop saw is lowered to the operational position while being partially collapsible in order to facilitate changing of the saw blade by allowing the protective blade guard to be swung out of position while the saw is maintained in the rest position. Additionally, the linkage system of the present invention engages a locking element when the saw unit is in its rest position in a manner that reduces the forces that must be absorbed by the locking element.
Additional advantages of the invention are set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.